This invention is in the field of both light sources and calendrical devices, and more specifically in the field of light sources for forming decorative light images, and devices which use sunlight to indicate the time of day and year.
Many kinds of calendrical devices which employ the sun, i.e., sun dials, are known. Most sundials operate by casting a shadow on a scale which indicates the time of day or year. However, some sundials operate by actually focusing the sunlight or forming an image of sunlight on a scale, from which the time of day can be determined. Such sundials are characterized by U.S. Pat. Nos. 3,815,249 and 4,338,727 to Gundlach. A related device is characterized by U.S. Pat. No. 2,668,357 to Whipple. Whipple teaches a device for measuring the length of sun exposure and is built up of lens-like structures which form a spot of light on a scale as the sun passes across the sky.
Although the sundial disclosed in Gundlach U.S. Pat. No. 3,815,249 is supported on a latitude ring which is adjustable to allow the axis of the sundial to be parallel with the earth's rotational axis, none of the above-described devices allow for the position of the light-catching mechanism to be adjusted to compensate for the changing position of the sun over the course of the year. Moreover, the above-described devices have extremely limited aesthetic appeal. The appearance of the devices themselves is dictated solely by utilitarian considerations, and the light image formed is only a small spot focused on the time scale.
There are also numerous devices known which are usable as a decorative light source. Many of these utilize artificial light, and are characterized by U.S. Pat. Nos. 1,984,986 to Prouty, 3,538,323 to Ziegler, 3,585,379 to Yamamoto et al., 3,783,035 to Bricker, 3,793,755 to Gersch et al., and 3,803,398 to Walker. Prouty teaches a display device comprising luminous tubing supported over a mirror for creating a specular image. Ziegler teaches a decorative light source in which light from a lamp passes through a rotating, multi-colored filter wheel and is then reflected by a rotating, contoured mirror. Yamamoto et al. teach a lighting fixture in which a bladed rotor is mounted above a bulb in an opaque hollow tube for producing a flamelike flickering light. Bricker teaches a lighted display in which light transmissive members are rotatably mounted over a light bulb to create intermittently pulsed streaks of light. Gersch et al. teach apparatus for producing moving light patterns comprising a light bulb, a rotatable light transmitting member having a multiplicity of light transmitting surfaces which receive light from the light bulb, and a multi-colored, rotatable, light-transmitting wheel mounted between the light bulb and the member. Walker teaches a lightbulb and a plurality of optical fibers bunched together at one end over the bulb for creating a light effect at the unbunched end. Because these devices are usable only with artificial lighting, they cannot be used for calendrical purposes.
Reflection and dispersion as taught by Ziegler have also been used, however, with natural sunlight, as described in U.S. Pat. No. 354,440 to Schoenberg. Schoenberg teaches an "incidence window" for indirectly lighting a room by reflecting sunlight through lenses and prisms. However, because the purpose of Schoenberg's window is lighting a room, the lenses and prisms are set up to fully diffuse the light, rather than to create a decorative light pattern. U.S. Pat. No. 3,068,754 to Benjamin teaches a related device, a light-transmitting ceiling panel comprising clusters of prisms for creating a fully-diffused pattern of light, substantially free from glare, from an artificial light source positioned above the ceiling panel. Thus, although Schoenberg and Benjamin both use the phenomena of diffusion, reflection, and dispersion of light, they do so in a manner which precludes a creation of decorative light images and any indication of the sun's movement. It is the solution of these and other problems to which the present invention is directed.
Therefore, it is the primary object of this invention to provide a combination decorative light image source and calendrical device which, upon exposure to direct sunlight, forms decorative light images for indicating the time of day and year.
It is another object of this invention to provide a decorative light image source and calendrical device which can be adjusted to place the light-catching mechanism to take into account the changing position of the sun throughout the year.
It is still another object of this invention to provide a decorative light image source and calendrical device which can create a decorative light image using artificial light when direct sunlight is not available.